U.S. patent application number 13/361234 was filed with the patent office on 2012-08-02 for deployable antenna.
This patent application is currently assigned to JAPAN AEROSPACE EXPLORATION AGENCY. Invention is credited to Kiyoshi FUJII, Satoru OZAWA, Kyoji SHINTATE, Minoru TABATA.
Application Number | 20120193498 13/361234 |
Document ID | / |
Family ID | 45524444 |
Filed Date | 2012-08-02 |
United States Patent
Application |
20120193498 |
Kind Code |
A1 |
TABATA; Minoru ; et
al. |
August 2, 2012 |
DEPLOYABLE ANTENNA
Abstract
A deployable antenna which has a larger aperture diameter by
four-side links provided in at least three stages and which
includes: six deployment link mechanisms (20) arranged radially
from a central shaft so as to support an outer edge portion of a
flexible reflector mirror surface; and one deployment driving
mechanism (30) arranged at a lower portion of a center of
arrangement of the six deployment link mechanisms, for unfolding
the six deployment link mechanisms. Each of the six deployment link
mechanisms includes a first four-side link (5), a second four-side
link (6), and a third four-side link (7) arranged in an order from
a position of the central shaft, around which the six deployment
link mechanisms are arranged, toward an outer side of the each of
the six deployment link mechanisms so that the each of the six
deployment link mechanisms is structured to be foldable in three
stages.
Inventors: |
TABATA; Minoru; (Tokyo,
JP) ; FUJII; Kiyoshi; (Tokyo, JP) ; SHINTATE;
Kyoji; (Ibaraki, JP) ; OZAWA; Satoru;
(Ibaraki, JP) |
Assignee: |
JAPAN AEROSPACE EXPLORATION
AGENCY
Tokyo
JP
NEC TOSHIBA Space Systems, Ltd.
Tokyo
JP
|
Family ID: |
45524444 |
Appl. No.: |
13/361234 |
Filed: |
January 30, 2012 |
Current U.S.
Class: |
248/346.3 |
Current CPC
Class: |
H01Q 15/161 20130101;
H01Q 1/288 20130101 |
Class at
Publication: |
248/346.3 |
International
Class: |
H01Q 1/08 20060101
H01Q001/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 31, 2011 |
JP |
2011-017529 |
Claims
1. A deployable antenna, comprising: six deployment link mechanisms
arranged radially from a central shaft of the deployable antenna so
as to support an outer edge portion of a flexible reflector mirror
surface of the deployable antenna; and one deployment driving
mechanism arranged at a lower portion of a center of arrangement of
the six deployment link mechanisms, for unfolding the six
deployment link mechanisms, wherein each of the six deployment link
mechanisms comprises a first four-side link, a second four-side
link, and a third four-side link arranged in an order from a
position of the central shaft, around which the six deployment link
mechanisms are arranged, toward an outer side of the each of the
six deployment link mechanisms so that the each of the six
deployment link mechanisms is structured to be foldable in three
stages, wherein a central vertical link member of the first
four-side link, which serves as the central shaft, comprises a
first slider, wherein a common vertical link member between the
first four-side link and the second four-side link comprises a
second slider, wherein another common vertical link member between
the second four-side link and the third four-side link comprises a
third slider, wherein the one deployment driving mechanism causes
the first slider to slide upwardly along the central vertical link
member, to thereby unfold the first four-side link, wherein the
unfolded first four-side link causes the second slider to slide
upwardly along the common vertical link member, to thereby unfold
the second four-side link, and wherein the unfolded second
four-side link causes the third slider to slide upwardly along the
another common vertical link member, to thereby unfold the third
four-side link.
2. A deployable antenna according to claim 1, wherein the first
four-side link comprises a link mechanism to be brought into an
extended state when the one deployment driving mechanism causes the
first slider to slide upwardly along the central vertical link
member, to thereby unfold the first four-side link.
3. A deployable antenna according to claim 1, wherein the first
four-side link further comprises a first promoting link member for
promoting unfolding of the first four-side link when the unfolded
first four-side link causes the second slider to slide upwardly
along the common vertical link member, and wherein the second
four-side link comprises a second promoting link member for
promoting unfolding of the second four-side link when the unfolded
first four-side link causes the second slider to slide upwardly
along the common vertical link member.
4. A deployable antenna according to claim 1, wherein the third
four-side link comprises a link mechanism to be brought into an
extended state when the unfolded second four-side link causes the
third slider to slide upwardly along the another common vertical
link member, to thereby unfold the third four-side link.
5. A jointed-type deployable antenna, comprising: a plurality of
the deployable antennas according to claim 1; and a plurality of
joint members for jointing outermost peripheral portions of the
plurality of the deployable antennas to one another.
6. A deployable antenna according to claim 1, wherein the each of
the six deployment link mechanisms further comprises a fourth
four-side link and a fifth four-side link arranged between the
second four-side link and the third four-side link so that the each
of the six deployment link mechanisms is structured to be foldable
in five stages, and wherein the fourth four-side link and the fifth
four-side link have substantially the same structures as the first
four-side link and the second four-side link.
7. A jointed-type deployable antenna, comprising: a plurality of
the deployable antennas according to claim 6; and a plurality of
joint members for jointing outermost peripheral portions of the
plurality of the deployable antennas to one another.
8. A deployable antenna, comprising: eight deployment link
mechanisms arranged radially from a central shaft of the deployable
antenna so as to support an outer edge portion of a flexible
reflector mirror surface of the deployable antenna; and one
deployment driving mechanism arranged at a lower portion of a
center of arrangement of the eight deployment link mechanisms, for
unfolding the eight deployment link mechanisms, wherein each of the
eight deployment link mechanisms comprises a first four-side link,
a second four-side link, and a third four-side link arranged in an
order from a position of the central shaft, around which the eight
deployment link mechanisms are arranged, toward an outer side of
the each of the eight deployment link mechanisms so that the each
of the eight deployment link mechanisms is structured to be
foldable in three stages, wherein a central vertical link member of
the first four-side link, which serves as the central shaft,
comprises a first slider, wherein a common vertical link member
between the first four-side link and the second four-side link
comprises a second slider, wherein another common vertical link
member between the second four-side link and the third four-side
link comprises a third slider, wherein the one deployment driving
mechanism causes the first slider to slide upwardly along the
central vertical link member, to thereby unfold the first four-side
link, wherein the unfolded first four-side link causes the second
slider to slide upwardly along the common vertical link member, to
thereby unfold the second four-side link, and wherein the unfolded
second four-side link causes the third slider to slide upwardly
along the another common vertical link member, to thereby unfold
the third four-side link.
9. A deployable antenna according to claim 8, wherein the each of
the eight deployment link mechanisms further comprises a fourth
four-side link and a fifth four-side link arranged between the
second four-side link and the third four-side link so that the each
of the eight deployment link mechanisms is structured to be
foldable in five stages, and wherein the fourth four-side link and
the fifth four-side link have substantially the same structures as
the first four-side link and the second four-side link.
Description
[0001] This application is based upon and claims the benefit of
priority from Japanese patent application No. 2011-017529, filed on
Jan. 31, 2011, the disclosure of which is incorporated herein in
its entirety by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a deployable antenna.
[0004] 2. Description of the Related Art
[0005] The deployable antenna is transported in a folded state
because of its limited stowage capacity during the transportation
from ground to orbit. After transported to the orbit, the
deployable antenna in the folded state is deployed as an antenna in
the orbit.
[0006] FIGS. 1, 2, and 3 are illustrations of a deployable antenna
A0 according to the related art. FIG. 1 is a view of the deployable
antenna A0 as obliquely viewed to its front surface. FIG. 2 is a
view of the deployable antenna A0 as obliquely viewed to its back
surface. FIG. 3 is a view illustrating the back surface of the
deployable antenna A0.
[0007] The deployable antenna A0 is a large deployable antenna
having an aperture diameter size exceeding 10 m. In the deployable
antenna A0 illustrated in the figures, a plurality of deployable
antenna modules A1 (FIG. 1) are jointed to and driven in
association with one another by joint members 40 (FIG. 3), to
thereby attain the deployable antenna having a large aperture
diameter. In the deployable antenna A0 illustrated in the figures,
deployment driving mechanisms 30 (FIGS. 2 and 3) are provided to
the respective deployable antenna modules A1, resulting in an
increase in number of the deployment driving mechanisms 30 to be
used, which are hard to reduce in weight. Consequently, there is a
disadvantage that the mass of the deployable antenna A0
increases.
[0008] As described above, the module diameter size of each
deployable antenna module A1 is smaller than the aperture diameter
size of the deployable antenna A0. Therefore, in order to obtain
the deployable antenna A0 having a large aperture diameter, a
plurality of deployable antenna modules A1 need to be jointed to
one another to increase the area of the antenna. However, in the
method of jointing a plurality of deployable antenna modules A1 to
one another to attain the deployable antenna A0, the number of the
deployment driving mechanisms 30 to be used for the deployable
antenna A0 increases, which leads to the disadvantage that the mass
of the entire antenna increases.
[0009] Japanese Unexamined Patent Application Publication (JP-A)
No. 2006-80577 discloses, in FIG. 3 and paragraphs [0024] and
[0025], that each frame 2 is constructed of five planar links 3,
and that the adjacent planar links 3 are jointed to each other in a
mirror-image relationship.
[0010] Further, Japanese Unexamined Patent Application Publication
(JP-A) No. 2006-80577 discloses, in FIG. 4 and paragraphs [0026],
[0028] to [0031], and [0033], that the slide hinge 7 of each planar
link 3 is moved by the wire driving device (extending means) 11
(corresponding to the deployment driving mechanism described above)
to fold and unfold the frame 2.
[0011] However, as illustrated in FIG. 4 of Japanese Unexamined
Patent Application Publication (JP-A) No. 2006-80577, the link
member 4c of each planar link 3 is provided with the slide hinge 7,
but the link member 4a opposed to the link member 4c is not
provided with any slider for synchronized unfolding between the two
adjacent planar links.
[0012] International Patent WO2005/027186A discloses, in FIG. 2 and
lines 21 to 24 of page 7, that each frame 2 is constructed of five
planar links 3, and that the adjacent planar links 3 are jointed to
each other in a mirror-image relationship.
[0013] Further, International Patent WO2005/027186A discloses, in
FIG. 3, lines 31 to 42 of page 7, and lines 48 to 50 of page 7,
that the slide hinge 7 of each planar link 3 is moved by the wire
driving device (extending means) 11 (corresponding to the
deployment driving mechanism described above) to fold and unfold
the frame 2.
[0014] However, as illustrated in FIG. 3 of International Patent
WO2005/027186A, the link member 4c of each planar link 3 is
provided with the slide hinge 7, but the link member 4a opposed to
the link member 4c is not provided with any slider for synchronized
unfolding between the two adjacent planar links.
[0015] Japanese Unexamined Patent Application Publication (JP-A)
No. Hei 11-112228 discloses, in FIGS. 1 and 2 and paragraph [0025],
the planar truss 1 in a state of being unfolded into a rectangular
shape.
[0016] However, as illustrated in FIG. 2 of Japanese Unexamined
Patent Application Publication (JP-A) No. Hei 11-112228, the
central member 21 of the planar truss 1 is provided with the slider
27, but the peripheral member 22 opposed to the central member 21
is not provided with any slider similarly to Japanese Unexamined
Patent Application Publication (JP-A) No. 2006-80577 and
International Patent WO2005/027186A.
[0017] Japanese Unexamined Patent Application Publication (JP-A)
No. 2003-95199 discloses, in FIGS. 1(a) and 1(b), FIG. 2, and
paragraph [0019], the deployable antenna in which the bone members
14 each having two four-node links 12 and 13 continuously connected
together are disposed around the central vertical beam member 11.
As illustrated in FIG. 4 of Japanese Unexamined Patent Application
Publication (JP-A) No. 2003-95199, in the disclosed deployable
antenna, the synchronization mechanism 19 serving as unfolding
synchronization means is provided to the central vertical beam
member 11 so as to be movable in the axial direction thereof. One
end of the synchronization cable 20 is fixed to the synchronization
mechanism 19, and the other end of the synchronization cable 20 is
fixed in the vicinity of the hinge of the inclined member 123 of
the four-node link 12 of the bone member 14 under a state in which
the synchronization cable 20 is looped around the guide pulley
201.
[0018] However, both the vertical beam member 122 opposed to the
central vertical beam member 11 and the vertical beam member 132
opposed to the vertical beam member 122 are not provided with any
slider similarly to Japanese Unexamined Patent Application
Publication (JP-A) No. 2006-80577 and International Patent
WO2005/027186A.
SUMMARY OF THE INVENTION
[0019] It is an object of this invention to provide a deployable
antenna having a larger aperture diameter by four-side links
provided in a plurality of stages.
[0020] According to this invention, it is possible to obtain a
deployable antenna, including:
[0021] six deployment link mechanisms arranged radially from a
central shaft of the deployable antenna so as to support an outer
edge portion of a flexible reflector mirror surface of the
deployable antenna; and
[0022] one deployment driving mechanism arranged at a lower portion
of a center of arrangement of the six deployment link mechanisms,
for unfolding the six deployment link mechanisms,
[0023] in which each of the six deployment link mechanisms includes
a first four-side link, a second four-side link, and a third
four-side link arranged in an order from a position of the central
shaft, around which the six deployment link mechanisms are
arranged, toward an outer side of the each of the six deployment
link mechanisms so that the each of the six deployment link
mechanisms is structured to be foldable in three stages,
[0024] in which a central vertical link member of the first
four-side link, which serves as the central shaft, includes a first
slider,
[0025] in which a common vertical link member between the first
four-side link and the second four-side link includes a second
slider,
[0026] in which another common vertical link member between the
second four-side link and the third four-side link includes a third
slider,
[0027] in which the one deployment driving mechanism causes the
first slider to slide upwardly along the central vertical link
member, to thereby unfold the first four-side link,
[0028] in which the unfolded first four-side link causes the second
slider to slide upwardly along the common vertical link member, to
thereby unfold the second four-side link, and
[0029] in which the unfolded second four-side link causes the third
slider to slide upwardly along the another common vertical link
member, to thereby unfold the third four-side link.
[0030] Further, according to this invention, it is possible to
obtain a deployable antenna, including:
[0031] eight deployment link mechanisms arranged radially from a
central shaft of the deployable antenna so as to support an outer
edge portion of a flexible reflector mirror surface of the
deployable antenna; and
[0032] one deployment driving mechanism arranged at a lower portion
of a center of arrangement of the eight deployment link mechanisms,
for unfolding the eight deployment link mechanisms,
[0033] in which each of the eight deployment link mechanisms
includes a first four-side link, a second four-side link, and a
third four-side link arranged in an order from a position of the
central shaft, around which the eight deployment link mechanisms
are arranged, toward an outer side of the each of the eight
deployment link mechanisms so that the each of the eight deployment
link mechanisms is structured to be foldable in three stages,
[0034] in which a central vertical link member of the first
four-side link, which serves as the central shaft, includes a first
slider,
[0035] in which a common vertical link member between the first
four-side link and the second four-side link includes a second
slider,
[0036] in which another common vertical link member between the
second four-side link and the third four-side link includes a third
slider,
[0037] in which the one deployment driving mechanism causes the
first slider to slide upwardly along the central vertical link
member, to thereby unfold the first four-side link,
[0038] in which the unfolded first four-side link causes the second
slider to slide upwardly along the common vertical link member, to
thereby unfold the second four-side link, and
[0039] in which the unfolded second four-side link causes the third
slider to slide upwardly along the another common vertical link
member, to thereby unfold the third four-side link.
[0040] According to this invention, it is possible to obtain the
deployable antenna having a larger aperture diameter by the
four-side links provided in the plurality of stages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] In the accompanying drawings:
[0042] FIG. 1 is a view of a deployable antenna according to the
related art as obliquely viewed to its front surface;
[0043] FIG. 2 is a view of the deployable antenna illustrated in
FIG. 1 as obliquely viewed to its back surface;
[0044] FIG. 3 is a view illustrating the back surface of the
deployable antenna illustrated in FIG. 1;
[0045] FIG. 4 is a perspective view of a deployable antenna
according to a first embodiment of this invention;
[0046] FIG. 5 is a perspective view of an antenna deploying
mechanism of the deployable antenna illustrated in FIG. 4;
[0047] FIG. 6 is a view illustrating a deployment link mechanism of
the antenna deploying mechanism illustrated in FIG. 5;
[0048] FIG. 7 is a view illustrating a four-side link situated at a
left end of the deployment link mechanism illustrated in FIG.
6;
[0049] FIG. 8 is a view illustrating a right end portion of the
four-side link situated at the left end of the deployment link
mechanism illustrated in FIG. 6, and a left end portion of a
four-side link situated at a center of the deployment link
mechanism;
[0050] FIG. 9 is a view illustrating a left end portion of the
four-side link situated at the left end of the deployment link
mechanism illustrated in FIG. 6;
[0051] FIG. 10 is a view illustrating a right end portion of a
four-side link situated at a right end of the deployment link
mechanism illustrated in FIG. 6;
[0052] FIG. 11 is a view illustrating a deployment driving
mechanism of the deployment link mechanism illustrated in FIG.
6;
[0053] FIG. 12 is a view illustrating a deployment link mechanism
to be used in a deployable antenna according to a second embodiment
of this invention; and
[0054] FIG. 13 is a perspective view of a deployable antenna
according to a third embodiment of this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0055] Now, embodiments of this invention are described in
detail.
[0056] FIG. 4 is an illustration of a deployable antenna A1'
according to a first embodiment of this invention. The deployable
antenna A1' alone may serve as a large deployable antenna
corresponding to the large deployable antenna A0 illustrated in
FIGS. 1 to 3.
[0057] The deployable antenna A1' is stowed in a folded state
inside a fairing of a launch vehicle, and is deployed in orbit to
form an antenna reflector mirror surface (flexible reflector mirror
surface 4), which is formed of a flexible film surface, into a
predetermined parabolic shape.
[0058] The deployable antenna A1' includes the flexible reflector
mirror surface 4, an antenna deploying mechanism 1 that supports an
outer edge portion of the flexible reflector mirror surface 4, and
bands 3. The flexible reflector mirror surface 4 serves as a front
surface of the deployable antenna A1'.
[0059] FIG. 5 is an illustration of the antenna deploying mechanism
1 of the deployable antenna A1' illustrated in FIG. 4.
[0060] The antenna deploying mechanism 1 includes six deployment
link mechanisms 20 arranged radially from a central shaft of the
antenna deploying mechanism 1 so as to support the outer edge
portion of the flexible reflector mirror surface 4 at six points,
and one deployment driving mechanism 30 arranged at a lower portion
of the center of arrangement of the six deployment link mechanisms
20. The deployment driving mechanism 30 is an actuator mechanism
part for unfolding the six deployment link mechanisms 20.
[0061] The bands 3 illustrated in FIG. 4 are provided so as to
adjust a phase angle of each deployment link mechanism 20.
[0062] FIG. 6 is an illustration of a single deployment link
mechanism 20 that is a component of the six deployment link
mechanisms 20 of the antenna deploying mechanism 1 illustrated in
FIG. 5.
[0063] The single deployment link mechanism 20 includes three
four-side links 5, 6, and 7 arranged in an order from the position
of the central shaft, around which the six deployment link
mechanisms 20 are arranged, toward an outer side of the deployment
link mechanism 20. Thus, the deployment link mechanism 20 is
structured to be foldable in three stages. In FIG. 6, black spots
represent hinge mechanisms.
[0064] Each deployable antenna module A1 of the deployable antenna
A0 illustrated as the related art in FIGS. 1 to 3 has an antenna
deploying mechanism similar to the antenna deploying mechanism 1
illustrated in FIG. 5. Specifically, the antenna deploying
mechanism of the deployable antenna module A1 (FIGS. 1 to 3) also
includes six radially arranged deployment link mechanisms 20 and
one deployment driving mechanism 30. However, the deployment link
mechanisms 20 of the deployable antenna module A1 (FIGS. 1 to 3)
are each constructed of the four-side link 7 alone (single
stage).
[0065] In contrast, according to the first embodiment, as
illustrated in FIG. 6, the deployment link mechanism 20 is
constructed of the four-side links 5, 6, and 7 (three stages:
foldable in three stages).
[0066] In FIG. 6, a link member (central vertical link member) 8 of
the four-side link 5, which serves as the central shaft, includes a
slider 9. A link member (common vertical link member) 15 between
the four-side links 5 and 6 includes a slider 16. Another link
member (another common vertical link member) 8 between the
four-side links 6 and 7 includes a slider 9.
[0067] In the single deployment link mechanism 20 illustrated in
FIG. 6, the four-side link 6 is jointed to the four-side link 5
serving as a support structure for the deployable antenna A1', the
four-side link 6 having a shape line-symmetric to that of the
four-side link 5. Further, the four-side link 7 is jointed to the
four-side link 6, the four-side link 7 having a shape
line-symmetric to that of the four-side link 6. As described above,
the three-fold structure is employed to increase an aperture
diameter size of the single deployable antenna A1'. Specifically,
the single deployable antenna A1' is structured to have an aperture
diameter size that is substantially three times as large as the
module aperture diameter size of the single deployable antenna
module A1 (FIGS. 1 to 3). The deployable antenna A1' alone may
serve as a large deployable antenna corresponding to the large
deployable antenna A0 illustrated in FIGS. 1 to 3.
[0068] In a case where the large deployable antenna A0 illustrated
in FIGS. 1 to 3 is constructed using the single deployable antenna
A1' illustrated in FIG. 4, only one deployment driving mechanism 30
is necessary for the large deployable antenna A0, with the result
that a lightweight, large deployable antenna is attained.
[0069] FIG. 7 is an illustration of the four-side link 5 situated
at the left end of the deployment link mechanism 20 illustrated in
FIG. 6.
[0070] The four-side link 5 is constructed of the link member 8 and
link members 13, 14, and 15. To the four-side link 5, the slider 9,
link members 10, 11, and 12, the slider 16, and a link member 17
are jointed through hinge mechanisms hg.
[0071] In FIGS. 6 and 7, the deployment driving mechanism 30 causes
the slider 9 to slide upwardly along the central vertical link
member 8 serving as the central shaft. Accordingly, the link member
10 brings the link members 11 and 12 into an extended state, to
thereby unfold the four-side link 5. The unfolded four-side link 5
causes the slider 16 to slide upwardly along the common vertical
link member 15, and accordingly the four-side link 6 is unfolded by
the link member 17. In this manner, the unfolded shape of the
four-side link 6 is synchronized with the unfolded shape of the
four-side link 5. As for the structure between the four-side link 6
and the four-side link 7, the unfolded four-side link 6 causes the
slider 9 to slide upwardly along the another common vertical link
member 8. Accordingly, the link member 10 brings the link members
11 and 12 into an extended state, to thereby unfold the four-side
link 7. In this manner, the unfolded shape of the four-side link 7
is synchronized with the unfolded shape of the four-side link
6.
[0072] FIG. 8 is an illustration of a right end portion of the
four-side link 5 situated at the left end of FIG. 6 and a left end
portion of the four-side link 6 situated at the center of FIG. 6.
The slider 16 moves vertically along the common vertical link
member 15. One end of the link member 17 is rotatably fixed to the
link member 14, and the other end of the link member 17 is
rotatably fixed to the slider 16.
[0073] FIG. 9 is an illustration of a left end portion of the
four-side link 5 situated at the left end of FIGS. 6 and 7.
[0074] FIG. 10 is an illustration of a right end portion of the
four-side link 7 situated at the right end of FIG. 6.
[0075] FIG. 11 is an illustration of the deployment driving
mechanism 30 of FIG. 6. The deployment driving mechanism 30
includes an actuator 31 (for example, a spring) for pushing the
slider 9 up in the unfolding direction (that is, upwardly along the
central vertical link member 8), and a damping device 32 (for
example, a wire to be driven by a motor) for controlling the
unfolding motion of the slider 9. Further, the four-side link may
be folded when the damping device 32 is moved in a reverse
direction.
[0076] Now, an operation of the above-mentioned first embodiment is
described.
[0077] In FIG. 7, the deployment driving mechanism 30 causes the
slider 9 to slide upwardly along the central vertical link member
8. Accordingly, the link member 10 brings the link members 11 and
12 into an extended state, to thereby unfold the four-side link 5
constructed of the link members 8, 13, 14, and 15.
[0078] The link members 11 and 12 in the extended state serve as a
structure for stably maintaining the shape of the four-side link 5
in the unfolded state.
[0079] In FIG. 7, the unfolding force to be imparted by the slider
16 promotes the unfolding force to be imparted by the slider 9, and
accordingly promotes the unfolding force of the entire deployment
link mechanism 20.
[0080] In FIG. 6, the four-side link 6 is line-symmetric to the
four-side link 5, and hence unfolded line-symmetrically to the
four-side link 5. Similarly, the four-side link 7 is unfolded
line-symmetrically to the four-side link 6. Thus, the deployment
link mechanism 20 constructed of the four-side links 5, 6, and 7 is
unfolded and folded in accordance with the sliding motion of the
sliders 9 and 16.
[0081] In the first embodiment, the deployment link mechanisms 20
foldable in three stages are used to provide a mechanism capable of
folding and unfolding the deployable antenna A1' having a large
aperture diameter.
[0082] The first embodiment enables the single deployable antenna
A1' to serve as a large deployable antenna, to thereby reduce the
weight of the large deployable antenna.
[0083] Note that, in order to obtain a deployable antenna having
such a large aperture diameter size that cannot be attained by the
single deployable antenna A1' according to the first embodiment,
similarly to the deployable antenna A0 of FIGS. 1 to 3, the
outermost peripheral portions of a plurality of deployable antennas
A1' (outermost peripheral portions of four-side links 7) only need
to be jointed to one another by a plurality of joint members 40
(FIG. 3) to construct a jointed-type deployable antenna having a
large aperture diameter size.
[0084] FIG. 12 is an illustration of a deployment link mechanism
20' to be used in a deployable antenna according to a second
embodiment of this invention. The deployment link mechanism 20' is
constructed of five four-side links 5, 6, 5, 6, and 7, to thereby
provide a deployment link mechanism foldable in five stages. The
deployment link mechanism 20' is obtained by adding two four-side
links 5 and 6 between the four-side links 6 and 7 of the deployment
link mechanism 20 of FIG. 6. The two added four-side links 5 and 6
have substantially the same structures as the four-side links 5 and
6 of the deployment link mechanism 20 of FIG. 6.
[0085] As described above, the five-fold structure is employed to
increase the aperture diameter size of the deployable antenna.
Specifically, the deployable antenna is structured to have an
aperture diameter size that is substantially five times as large as
the module aperture diameter size of the deployable antenna module
A1 (FIGS. 1 to 3). The deployable antenna alone may also serve as a
large deployable antenna corresponding to the large deployable
antenna A0 illustrated in FIGS. 1 to 3.
[0086] Note that, in order to obtain a deployable antenna having
such a large aperture diameter size that cannot be attained by the
single deployable antenna according to the second embodiment,
similarly to the deployable antenna A0 of FIGS. 1 to 3, the
outermost peripheral portions of a plurality of deployable antennas
(outermost peripheral portions of four-side links 7) only need to
be jointed to one another by a plurality of joint members 40 (FIG.
3) to construct a jointed-type deployable antenna having a large
aperture diameter size.
[0087] Now, referring to FIGS. 4 to 7 and 12, various structures of
the deployable antenna according to the first and second
embodiments are summarized in the following items (1) to (7):
[0088] (1) A deployable antenna, including:
[0089] six deployment link mechanisms 20 arranged radially from a
central shaft of the deployable antenna so as to support an outer
edge portion of a flexible reflector mirror surface 4 of the
deployable antenna; and
[0090] one deployment driving mechanism 30 arranged at a lower
portion of a center of arrangement of the six deployment link
mechanisms 20, for unfolding the six deployment link mechanisms
20,
[0091] in which each of the six deployment link mechanisms 20
includes a first four-side link 5, a second four-side link 6, and a
third four-side link 7 arranged in an order from a position of the
central shaft, around which the six deployment link mechanisms 20
are arranged, toward an outer side of the each of the six
deployment link mechanisms 20 so that the each of the six
deployment link mechanisms 20 is structured to be foldable in three
stages,
[0092] in which a central vertical link member 8 of the first
four-side link 5, which serves as the central shaft, includes a
first slider 9,
[0093] in which a common vertical link member 15 between the first
four-side link 5 and the second four-side link 6 includes a second
slider 16,
[0094] in which another common vertical link member 8 between the
second four-side link 6 and the third four-side link 7 includes a
third slider 9,
[0095] in which the one deployment driving mechanism 30 causes the
first slider 9 to slide upwardly along the central vertical link
member 8, to thereby unfold the first four-side link 5,
[0096] in which the unfolded first four-side link 5 causes the
second slider 16 to slide upwardly along the common vertical link
member 15, to thereby unfold the second four-side link 6, and
[0097] in which the unfolded second four-side link 6 causes the
third slider 9 to slide upwardly along the another common vertical
link member 8, to thereby unfold the third four-side link 7.
[0098] (2) A deployable antenna according to the above-mentioned
item (1), in which the first four-side link 5 includes link
mechanisms 10, 11, and 12 to be brought into an extended state when
the one deployment driving mechanism 30 causes the first slider 9
to slide upwardly along the central vertical link member 8, to
thereby unfold the first four-side link 5.
[0099] (3) A deployable antenna according to the above-mentioned
item (1) or (2),
[0100] in which the first four-side link 5 further includes a first
promoting link member 17 for promoting unfolding of the first
four-side link 5 when the unfolded first four-side link 5 causes
the second slider 16 to slide upwardly along the common vertical
link member 15, and
[0101] in which the second four-side link 6 includes a second
promoting link member 17 for promoting unfolding of the second
four-side link 6 when the unfolded first four-side link 5 causes
the second slider 16 to slide upwardly along the common vertical
link member 15.
[0102] (4) A deployable antenna according to any one of the
above-mentioned items (1) to (3), in which the third four-side link
7 includes link mechanisms 10, 11, and 12 to be brought into an
extended state when the unfolded second four-side link 6 causes the
third slider 9 to slide upwardly along the another common vertical
link member 8, to thereby unfold the third four-side link 7.
[0103] (5) A jointed-type deployable antenna, including:
[0104] a plurality of the deployable antennas A1' according to any
one of the above-mentioned items (1) to (4); and
[0105] a plurality of joint members 40 (FIG. 3) for jointing
outermost peripheral portions of the plurality of the deployable
antennas to one another.
[0106] (6) A deployable antenna according to the above-mentioned
item (1),
[0107] in which the each of the six deployment link mechanisms 20'
further includes a fourth four-side link 5 and a fifth four-side
link 6 arranged between the second four-side link 6 and the third
four-side link 7 so that the each of the six deployment link
mechanisms 20' is structured to be foldable in five stages, and
[0108] in which the fourth four-side link 5 and the fifth four-side
link 6 have substantially the same structures as the first
four-side link 5 and the second four-side link 6.
[0109] (7) A jointed-type deployable antenna, including:
[0110] a plurality of the deployable antennas according to the
above-mentioned item (6); and
[0111] a plurality of joint members 40 (FIG. 3) for jointing
outermost peripheral portions of the plurality of the deployable
antennas to one another.
[0112] FIG. 13 is an illustration of a deployable antenna A1''
according to a third embodiment of this invention. The deployable
antenna A1'' is an octagonal deployable antenna obtained by
radially providing the deployment link mechanisms 20 at eight
points so as to support the outer peripheral edge portion of the
flexible reflector mirror surface 4 at eight points. The octagonal
deployable antenna A1'' has such an elliptical aperture shape that
an axial projection shape of the parabola of the flexible reflector
mirror surface 4 is formed into a circular aperture. Each of the
deployment link mechanisms 20 provided at eight points has a
similar structure as that of FIGS. 6 and 7.
[0113] Note that, in the deployable antenna A1'' illustrated in
FIG. 13, the deployment link mechanism 20' illustrated in FIG. 12
may be used as each of the eight deployment link mechanisms 20. As
described above, the deployment link mechanism 20' is constructed
of five four-side links 5, 6, 5, 6, and 7, to thereby provide a
deployment link mechanism foldable in five stages. The deployment
link mechanism 20' is obtained by adding two four-side links 5 and
6 between the four-side links 6 and 7 of the deployment link
mechanism 20 of FIG. 6. The two added four-side links 5 and 6 have
substantially the same structures as the four-side links 5 and 6 of
the deployment link mechanism 20 of FIG. 6.
[0114] Now, referring to FIGS. 13, 6, 7, and 12, various structures
of the deployable antenna A1'' according to the third embodiment
are summarized in the following items (8) and (9):
[0115] (8) A deployable antenna A1'', including:
[0116] eight deployment link mechanisms 20 arranged radially from a
central shaft of the deployable antenna so as to support an outer
edge portion of a flexible reflector mirror surface 4 of the
deployable antenna; and
[0117] one deployment driving mechanism 30 arranged at a lower
portion of a center of arrangement of the eight deployment link
mechanisms 20, for unfolding the eight deployment link mechanisms
20,
[0118] in which each of the eight deployment link mechanisms 20
includes a first four-side link 5, a second four-side link 6, and a
third four-side link 7 arranged in an order from a position of the
central shaft, around which the eight deployment link mechanisms 20
are arranged, toward an outer side of the each of the eight
deployment link mechanisms 20 so that the each of the eight
deployment link mechanisms 20 is structured to be foldable in three
stages,
[0119] in which a central vertical link member 8 of the first
four-side link 5, which serves as the central shaft, includes a
first slider 9,
[0120] in which a common vertical link member 15 between the first
four-side link 5 and the second four-side link 6 includes a second
slider 16,
[0121] in which another common vertical link member 8 between the
second four-side link 6 and the third four-side link 7 includes a
third slider 9,
[0122] in which the one deployment driving mechanism 30 causes the
first slider 9 to slide upwardly along the central vertical link
member 8, to thereby unfold the first four-side link 5,
[0123] in which the unfolded first four-side link 5 causes the
second slider 16 to slide upwardly along the common vertical link
member 15, to thereby unfold the second four-side link 6, and
[0124] in which the unfolded second four-side link 6 causes the
third slider 9 to slide upwardly along the another common vertical
link member 8, to thereby unfold the third four-side link 7.
[0125] (9) A deployable antenna according to the above-mentioned
item (8),
[0126] in which the each of the eight deployment link mechanisms 20
further includes a fourth four-side link 5 and a fifth four-side
link 6 arranged between the second four-side link 6 and the third
four-side link 7 so that the each of the eight deployment link
mechanisms 20 is structured to be foldable in five stages, and
[0127] in which the fourth four-side link 5 and the fifth four-side
link 6 have substantially the same structures as the first
four-side link 5 and the second four-side link 6.
[0128] This invention is applicable to a folding mechanism of a
deployable antenna, of the parabolic antennas to be mounted onto an
artificial satellite or the like.
[0129] This invention has been described above in detail with
reference to the embodiments, but this invention is not limited to
the embodiments described above. Various modifications
understandable for a person having ordinary skill in the art may be
made to the structures and details of this invention within the
scope of this invention.
* * * * *